What causes cerebral effusion?

The hydrocephalus you mentioned should be what we call hydrocephalus clinically. In clinical terms, there is no hydrocephalus, only hydrocephalus. Hydrocephalus is mainly caused by the absorption disorder of cerebrospinal fluid on the surface of the brain and the blockage of cerebrospinal fluid in the process of ventricular and central canal circulation. Hydrocephalus can be divided into two situations: 1. Communicating hydrocephalus, mainly due to the problem of reabsorption of cerebrospinal fluid by arachnoid particles; 2. Obstructive hydrocephalus, caused by blocked circulation of cerebrospinal fluid. The main causes are intracranial infection, cerebral hemorrhage, subarachnoid hemorrhage, intracranial tumor, etc.